Method and apparatus for the production of envelopes with gummed closing flaps



July 12, 1960 Filed May 6, 1958 w. DOETSCH 2,944,470 METHOD ANDAPPARATUS FOR THE PRODUCTION OF ENVELOPES wrm GUMMED CLOSING FLAPS 4Sheets-Sheet l W. DOETSCH METHOD AND APPARATUS FOR THE PRODUCTION OFJuly 12,1960

ENVELOPES WITH GUMMED CLOSING FLAPS 4 Sheets-Sheet 2 Filed May 6, 195822min & 3

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lnrenlar W/A #64 M 0057-507 5 W W y 1960 w. DOETSCH 2,944,470

METHOD AND APPARATUS FOR THE PRODUCTION OF ENVELOPES WITH GUMMED CLOSINGFLAPS Filed May e, 1958 4 Sheets-Sheet s nya In yenlar w/z/va/vwzzs'osJuly 12, 1960 w, DQETSCH 2,944,470

METHOD AND APPARATUS FOR THE PRODUCTION OF ENVELOPES WITH GUMMED CLQSINGFLAPS Filed May 6, 1958 4 Sheets-Sheet 4 f States' Fatemj 1 g enema Ju y12, 9

METHOD AND APPARATUS FOR THE PRODUC- TION F ENVELOPES WITH GUMMED CLOS-ING FLAPS I Wilhelm Doetsch, Augustinusstrasse 11, Neuss (Rhine),

Germany Filed May 6, 1958, Ser. No. 733,305

Claims priority, application Germany June 13, 1957 2 Claims. (CI; 93-62)For'producing letter envelopeswith gummed closing flaps a method isknown according to which the blanks taken from a pile of sheets areheated over a heating drum on the side remote from the gummed side withthe object of heating the edges of the closing flaps to be gummed. Inthis method in which the stacked blanks are conducted over the heatingdrum, the heat must always pene- I W irate through the whole pile ofpaper so as to heat the freely projecting edges of the flaps. A'saresult it'may happen', especially in the case of thick paper, thatthesheets located nearest the heating element become hardening andheating the surfaces of the closing flaps to be gumn led;

Fig. 5 shows a device for straightening up the blanks in top plan view,and I I Fig. 6 is a top plan view of a device for folding over the sideand bottom flaps.

According to the method illustrated by way of example in Fig. 1, instage I the blanks are withdrawn from the pile of blanks according tothe gulmmed width of the edges of the closing flaps and are brought by aconveyor track into the position necessary'for applying the gum. Afterthe surfaces of the closing flaps which are to be gummed have beensmoothed and heated, the application of the gum on these heatedsurfacesof the closing flaps is scorched, whereas the uppermost flaps arenot-sufficiently heated to dry the gum which is subsequentlyapplied} fThe object of the invention is to devise a method of producing envelopeswherein the above-mentioned objections are overcomeand importantadvantages both'fro'm a technical as well'as from an economical point.of view are attained; 1

'The method according to the invention ischaractertized in that theblanks taken from a pile of sheets oraroll of paper and cut to shape andsize are assembled in a continuous paper web with the edgesof theclosing flaps staggered one below the otherand one behind the "other,

and the exposed surfaces of the flaps tobe gummed are smoothed, hardenedand heated by an ironing process, the gum is then applied on thesmoothed heated flap sur faces and dried, whereupon the foremost anduppermost i of the blanks forming the layer of gummed' blanks isstraightened up, thereby widening the spacing of the staggering, iswithdrawn from the layer of blanks and then finally folded and stuckdown. I

,The method according to the invention possesses the advantage thatpreferably onlythe surfaces oftheclosing flaps to be gummed are heatedand at the same time the surface of the paper to be gummed issmoothedand hardened. The gum subsequently app-lied cannot thereforepenetrate the paper and hardens directly on the heated surface. T hedrying process is thereby considerably accelerated. Moreover thequantity of gum to be applied can be far less.

The invention also relates to a machine or anapparatus for carrying outthis new method and comprises a device for, receiving the pile composedof blanks cut to shape and size, a device for removing the blanks fromthe pile, a conveying device for transporting the blanks, a device forindividually separating the blanks and a device for folding and stickingthe envelopes.

The machine is characterized in that it comprises means tion, means forsmoothing and hardening as wellas heat ing the surfaces of theclosingfiaps to be gunnned, means for straightening up the blanks in theposition necessary for folding andsticking, and, means for folding'iandsticking the. side and bottom flaps.

Other-.featuresuof the invention will be hereinafter disfor pulling theblanks from the pile in staggered formar carried out in stage II.Instage III the applied gum dries and the staggering is widenedslightly, whereupon the blank which is actually foremost and uppermostis quickly straightened up'and withdrawn from the layer of blanks and isthen in stage 1V. In the subsequent stages V to Vllof the method, theside flaps a are folded over, the gum b is applied for subsequentlysticking the bottom flap c, the bottom fiap'c is folded over and theclosing flap closed.

As can be seen from Fig. 2, the lowermost blank of the pile 1 is grippedby the suction holes 2 in the suction shaft 3 at the point of the bottomflap and bent away from the pile. As soon as the bent portion of theblank comes within the range of the compressed air nozzles 4 it isforced by the compressed air passing out of the nozzles on to a belt 5which is driven by the cylinders 6, 7' and guided over the rollers 8, 9and 10. When the blank arrives on the belt 5 with its bottom flap inadvance, the rollers 11 move'towards the pile of blanks 1 and pull theblank forward a distance corresponding to the width of that portion ofthe closing flap to be gummed. While the blank is being carried along,the rollers 11 return into their initial position, the next followingblank being withdrawn from the pile 1 (Fig. 3) by the suction shaft '3and fed to the rollers 11 now again moving towards the pile .1. I

The layer of blanks staggered by the belt 5 and th rollers 11 is thenguided under the conveyor belt 14 driven by the drum 13 and passes overthis drum 13 between the pairs of belts 5 and 14. The free edges of theclosing flaps are smoothed out, hardened and heated by means of theironing plate 15 (Fig. 4) movably mounted on the shaft 16. Thereupon thegum is applied on the smoothed and heated surfaces of the closing flapsby means of the cylinder 18 mounted in the gum bath 17. The layer ofstaggered and gummed blanks passing out from between the pairs ofconveyor belts 5, 1 4 is taken over by the disc wheels 19 and therollers 20. The supplementary rollers 21 assist the layer in running inunder the belts 22. The speed of the disc wheels 19 and of the conveyorbelts 22 is somewhat higher than that of the conveyor belts 5, 14,- sothat the staggering spacing is slightly increased and the edges of theclosing flaps do not stick together. The conveyor belts 22 are driven bythe cylinders 23' and 24 and guided by the rollers 25, 26,

27 and 28. The heated edges of the closing flaps are cooled and the gumdried completely on the path to the cylinder 29 by means of cold air,fed through the passage 7 porarily on the belts 22, is taken over by therollers 32, 33 and passed on to the conveyor belt 34 running at a higherspeed and the counter rollers 35. These rollers 35 are adjustable insucha manner that they can grip the foremost and uppermost blank when it isreleased by the rollers, 33. I The conveyor belt 34 is driven at suchaspeed that although the blanks still remain, staggered, the spacing oftheir staggering is considerably increased. From this layer of staggeredblanks the foremost blank is picked up by its flap trailing behind withthe aid of the suction shaft 36 provided with suction aperture 37 and islifted off the layer of blanks. Fingers 39 (Fig. are provided on rollers38 and grip the blank at its rear fold corner incisions and carry it tothe withdrawing cylinders 40, 41, at the same time dressing orstraightening it up, whereupon these cylinders promptly withdraw itcompletely from the layer of blanks. The upper withdrawing cylinder 43is equipped with blades 42, 43 adj ustable in relation to each other andhas in its peripheral surface an aperture which allows the free entranceof the advance bottom flap. As the blank passes between the, rollers 40,41 it is creased by means of the creasing blades 42, 43 to facilitatethe subsequent folding over of the bottom and closing flaps. In passingfrom the cylinders 44, 45 to the cylinders 46, 47 the blank comes underthe folding blades 48 (Fig. 6) which are adjustable in such a mannerthat the distance between their outer edges corresponds to the creaselines for the side flaps. The travel to the cylinders '46, '47 isassisted by the conveyor belt 49 with the counter rollers 50. With theaid of compressed air nozzles 51 the two side flaps located outside thecrease lines are raised, then folded over between the cylinders 44, 46by belts 53 circulating in the form of a loop over the cylinders 45, 46and 52 and finally pressed down in passing between the cylinders 46, 47.The loop shape of the endless circulating belts 53 is produced by thefact that the contact side is reversed in the upper strand like a Mobiusbelt. The envelope blank continues to travel towards the conveyor andfolding cylinder 54 and is gripped by the suction apertures 55 directlybehind the crease line for the bottom flap. At the same time the pointof the bottom flap pointing ahead is raised by compressed air passingout of the aperture 56 and is guided over the creasing shaft 57. Gum ispreviously applied to the front edges of the side flaps by the gummingdevice 58 which receives gum from the cylinders 66 mounted in the gumbath 59. The envelope running out from between the cylinders 54, 57passes over a guide plate 61 between the cylinders 62, 63 and isconducted thereby into the folding pocket 64. Adjustable abutments 65are arranged in the folding pocket 64 and determine the height of thefold, and in the course of the further transport of the envelope betweenthe cylinders 62, 63 the closing flap is folded over between thecylinders 62, 66, the direction of travel of the envelope being thereby'reversed. The finished folded envelope running out frombetween thecylinders 62, 66 is then guided by the curved plate 67 between theconveyor belts running over the cylinders 68, 69 and 70 and the disc 72,from which it is conveyed by the plate 73 against the adjustable stops74 and stood on the delivery table 75.

I claim:

1. Machine for producing 'gummed envelopes comprising, in combination,means for withdrawing blanks individually and successively from a sourceof supply and forming a continuous web of blanks arranged in staggeredformation having the edges of the closing flaps to be gummed exposed,means for smoothing, hardening and heating said exposed edges, means forapplying gum to said heated edges, means for cooling said gummed edges,means for straightening up and advancing the foremost and uppermost'blank of the web, means for removing the advanced blanks successivelyfrom the web, means for folding over the side flaps of the blank, meansfor applying gum for sticking the side flaps and the bottom flap of eachblank, means for folding over the bottom flap, means for folding overthe closing flap and means for collecting the finished folded envelopes,and a transporting system interconnecting said aforementioned means,said means for smoothing, hardening and heating said exposed edgesincluding a flat ironing device arranged in the path of said web adaptedto engage .the surfaces of the said exposed edges to be gummed,subsequent to said means for withdrawing said blanks, and preceding saidmeans for applying gum, said straightening up and removing means furthercomprising a rotary suction shaft for raising up the foremost blank ofthe gummed web and a rotary cam shaft cooperating with said suctionshaft for straightening and discharging the raised blank from the web.

,2. Machine for producing gummed envelopes comprising, in combination,means for withdrawing blanks individually and successively from a sourceof supply and forming a continuous web of blanks arranged in stag-vgered formation having the edges of the closing flaps to be gummedexposed, means for smoothing, hardening and heating said exposed edges,means for applying gum to said heated edges, means for cooling saidgummed edges, means for straightening up and advancing the foremost anduppermost blank of the web, means for removing the advanced blankssuccessively from the web, means for folding over the side flaps of theblank, means for applying gum'for sticking the side flaps and the bottomflap of each blank, means for folding over the bottom flap, means forfolding over the closing flap and means for collecting the finishedfolded envelopes, and a transporting system interconnecting saidaforementioned means, said means for smoothing, hardening and heatingsaid exposed edges including a flat ironing device arranged in the pathof said web adapted to engage the surfaces of the said exposed edges tobe gummed, subsequent to said means for withdrawing said blanks, andpreceding said means for applying gum, 'said side flap folding meansfurther comprising belt loops for folding over the side flaps of theenvelopes and air nozzles coordinated to these loops for lifting the twoside flaps outside the folding lines.

References Cited in the file of this patent UNITED STATES PATENTS307,079 Sickels Oct. 21, 1884 2,367,856 Ettl Jan. 23, 1945 2,746,364Welsh May 22, 1956 2,770,176 Novick Nov. 13, 1956 2,791,161 Doetsch May7, 1957 FOREIGN PATENTS 172,287 Germany June 21, 1906

